#!/usr/bin/perl
use Benchmark qw(cmpthese timethese);

sub iterate {
  open(FILE, ">", "file.txt");
  for ($i = 0; $i < 1000000; $i ++) {
      print FILE $i++;
  }
  close(FILE);
}

sub lex_iterate {
  open(FILE, ">", "file.txt");
  for (my $i = 0; $i < 1000000; $i ++) {
      print FILE $i++;
  }
  close(FILE);
}

sub int_iterate {
  use integer;
  open(FILE, ">", "file.txt");
  for (my $i = 0; $i < 1000000; $i ++) {
      print FILE $i++;
  }
  close(FILE);
}


my $results = timethese(5 , { iterate=>\&iterate , lex_iterate=>\&lex_iterate, int_iterate=>\&int_iterate } );
cmpthese($results);

__END__
Benchmark: timing 5 iterations of int_iterate, iterate, lex_iterate...
int_iterate:  4 wallclock secs ( 4.03 usr +  0.06 sys =  4.09 CPU) @  1.22/s (n=5)
   iterate: 17 wallclock secs (16.70 usr +  0.07 sys = 16.77 CPU) @  0.30/s (n=5)
lex_iterate: 15 wallclock secs (15.20 usr +  0.08 sys = 15.28 CPU) @  0.33/s (n=5)
            s/iter     iterate lex_iterate int_iterate
iterate       3.35          --         -9%        -76%
lex_iterate   3.06         10%          --        -73%
int_iterate  0.818        310%        2